const buf1 = Buffer.alloc(10);
console.log('buf1: ', buf1);
const buf2 = Buffer.from('a');
console.log('buf2: ', buf2);

const buf3 = Buffer.from('汉');
console.log('buf3: ', buf3);

const buf4 = Buffer.concat([buf2, buf3]);
console.log('buf4: ', buf4.toString());


